Alcaligenes Eutrophus as a Source of Hydrogenase: An Evaluation of Techniques forIts Large Scale Production

摘要

Alcaligenes eutrophus H16 (ATCC 17699), an aerobic H2 oxidizing bacteria, hasbeen selected as the most suitable enzyme source for a NAD-linked soluble hydrogenase. The hydrogenase will be used to study the feasibility of biochemical decompression in hydrogen dive experiments. The choice of this enzyme was based on its ability to oxidize molecular hydrogen to water and its exceptional O2-resistance under general physiological conditions. Methods for growing A. eutrophus in the absence of externally supplied hydrogen have been reviewed with special consideration for their adaptability for mass production of the microorganism under safe conditions. Two methods that avoid the handling of large quantities of inflammable H2 mixtures have been compared and tested in this pilot study. One was the chemolithotrophic method of Schuster Schlegel, which involved the cultivation of bacteria in a mineral medium under electrolytically produced H2 and O2, and externally supplied CO2; the other was the heterotrophic procedure of Frederick and coworkers, which avoided H2 altogether but supplied the culture medium with fructose and glycerol as energy and carbon sources. Because of its simplicity, rapidity, high yield, and easy adaptability for large scale production, the heterotrophic method was selected. This method is expected to provide the required amount of enzyme for further development of the current research project. (js)